The yokes of solenoids currently in use are generally in the form of a horseshoe whose central part supports either the fixed core supporting the two windings or an opening to allow passage of the movable core. The free ends of the side arms of the yoke are connected by a piece of ferromagnetic material, attached to them by crimping, and supporting, opposite the middle part, the opening to allow passage of the movable core or the fixed core.
Thus, this yoke has gaps at two points which are oriented transversely to the direction of the magnetic flux and which consequently block its passage.